Body very long and thin, of equal width, posteriorly tapered. Prostomium rounded, longer than wide. Median antenna shorter than paired ones, situated well in front of the medium-sized eyes. Proboscis very long and thin, covered with diffusely distributed papillae. Tentacular cirri of segment 1 reaching about segment 3. Dorsal tentacular cirri of segments 2 and 3 reaching about segment 5. Ventral tentacular cirri slightly flattened, reaching about segment 3. Chaetae present from segment 2. Dorsal cirri of median segments ovoid, inflated. Chaetigerous lobes rounded, with about 10-15 chaetae. Terminal end of chaetal shaft with a number of rather similar-sized teeth, slightly decreasing in size proximally. Blades rather long and slender. Capillaries may occur on posterior segments. Ventral cirri rounded, slightly longer than chaetigerous lobes. Pygidial cirri cylindrical, about three times as long as wide with rounded tips. Median pygidial papilla present (E. tripunctata-detail).
Living relaxed specimen 50 mm long, 0.6 mm wide (chaetae excluded), for 250 segments.
Living animals faint yellowish. Three greenish black spots dorsally on every segment: one medial and two lateral. Lateral ones present from segment 1, median from about segments 4-5. On the ventrum only lateral spots, less distinct. Eyes clear red. Preserved animals darker, especially the dorsal cirri. Pigmentation pattern preserves well. Eyes dark brown.
Intertidal and subtidal in shell gravel, crevices, among stones and kelp holdfasts.
North east Atlantic up to the Mediterranean, East Scotland and North-East England.